This invention relates to a replaceable eye-protecting lens system for breathing masks that is easy to handle and ensures a firm and safe, i.e. gas-tight fit of the lenses in the body of the mask.
The state of the art includes a multitude of solutions wherein the fit of mask body and lens or lenses is ensured by inserting the one into a groove of the other and connecting them with a fastening means. For example, DE 92 18 061 U1 features a sealing rim for a solid mask body that comprises a bracket to join said sealing rim with a fastening clip. The disadvantage of this solution is that manufacturing the components is expensive and complicated, manual assembly is difficult, and the joint is relatively large in design, which diminishes the wearer""s field of vision. Another joining solution known from the market is that groove-shaped recesses in the mask body and groove-shaped recesses in the eye-protecting lens are nested and a wire-shaped fastener snaps shut. The disadvantage of this solution is the relatively large design and the fact that the mask body and lens are joined on the outer side of the mask, requiring the joint to be highly resistant to chemicals and making it contamination-prone.
It is the object and problem of this invention to create a replaceable eye-protecting lens system that provides a wide field of vision for the person wearing the mask and a mechanically firm and gas-tight fit of mask body and lens.
This problem is solved according to the invention by creating a replaceable lens system for breathing masks wherein a groove-shaped holding fixture is placed on the rim of eye-protecting lens that holds a fastening element of the mask body and a locking ring.
The solution according to the invention provides a replaceable lens system that has small dimensions, ensures a wide field of vision for the person wearing the mask, and ensures both a safe and gas-tight fit of mask body and eye-protecting lens and automatic manufacturing.